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G. H. DOUGHERTY.

Device for Stopping Engines.

NQ. 236,004. Patented Dec.- 28,1880.

UNITED STATES PATENT OFFICE.

GEORGE H. DOUGHERTY, OF JERSEY CITY, NEW JERSEY.

DEVICE FOR STOPPING ENGINES.

SPECIFICATION forming part of Letters Patent No. 236,004, dated December 28, 1880.

Application filed June 28, 1880.

To all whom fit may concern:

Be it known that I, GEORGE H. DOUG-H- ERTY, a citizen 'of the United States, residing in Jersey City, count)V of Hudson, and State of New Jersey, have invented certain new and useful Improvements in Devices for Stopping Engines, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

In said drawings, Figure l is a front elevation, partly in section, of an apparatus embodying my improvements. Fig. 2 shows a side elevation ofthe same, and Fig. 3 is a sectional elevation of one of the parts.

It is the object of this invention to prevent the occurrence of accidents which are imminent whenever the governor of an engine becomes inoperative to control the action ofthe motive agent.

The invention consists in a mechanism which will automatically operate to quickly cut off the motive agent wherebythe engine is driven.

whenever the governor fails to act by reason of the breaking or slipping of its belt or otherwise, and thus ceases to control the quantity of the motive agent allowed to pass into the cylinder and act upon the piston.

As illustrated herein, my improved cut-off mechanism is shown as applied to an ordinary steam-en gine. rIhe steam-pipe 20, that leads to the cylinder, is provided, as is usual,with a valve for regulating the quantity of steam that enters the cylinder, which valve (not shown) is moved, as is well understood, to diminish or increase the size of the induction-opening, by means of a rod, 10, which is raised or lowered by the action of thegovernor, according as the speed at which its weighted arms 30 40 are rotated increases or diminishes and the circle in which said arms travel is widened or narrowed.

The plug` 9 of the stop-valve that controls the admission of steam to the pipe 20 is constructed, asis usual, so as to be operated by a screw-threaded valve-rod, 21, and a hand- Wheel, 22.

Whenever the governor ceases to operate to control the action of the steam upon the piston the uniform velocity of the engine not only ceases, but the arms ofthe governor drop in- Ward, and thus open the induction-passage to (N0 model.)

its fullest extent, whereupon the steam is uncontrolled and exerts its full power upon the piston, thereby rapidly increasing the speed of the engine and rendering it liable to speedy destruction. When the governor thus becomes inactive it is necessary to quickly cut off the steam by closing the stop-valve. This is accomplished automatically by the following means:

The valve-rod 2l is provided beyond the hand-wheel 22 with a polygonal shaft, 6, (inadesquare in the present iustance,) thatis centered atits inner end by means of a circular stem which enters into a recess in the rod 21, and is supported at its outer end by means ofa bearing provided in a standard, 3l. The wheel 22 and rod 2l may thus move longitudinally' without being disconnected from the shaft (5, and the latter, while prevented from moving longitudinally by means of a journal, 8, in the circumferential groove of which a holdingscrew, 1l, enters, may beheld stationary therein by properly operating said screw ll.

i A drum, 50, rigidly secured to the wheel 22 by arms 12, is mounted so as to turn freely about the shaft 6. The walls of this drum embrace a collar, 5, that is mounted upon the polygonal parts of the shaft 6 so as to slide freely thereon, but be rotated by said shaft whenever it is turned. Within the drum a strong spiral spring, 23, is arranged, oneend thereof being secured to the inner periphery of the rim of said drum and the other end secured to the collar 5. Whenever the hand-wheel 22 is revolved the drum and its internal devices move with it by sliding upon the shaft 6, and vice versa; and it will therefore be apparent that it' the shaft 6 be held stationary by the set-screw ll and said wheel be turned so as to open the stop-valve its revolutions will wind 11p the spring 23, the reaction of which would operate to turn the wheel in the opposite direction, and thus close said valve. To practically utilize this action, devices connecting the drum with the governor are provided as follows:

A bell-crank lever is mounted so as to turn freely upon the outer end of a fixed shaft, 24, one arm, 13, of said lever being provided with a dog, l5, that may engage a tooth, 4, provided upon the perimeter of the drum 50,

IOO

while the other arm, 14, may rest against a cam, 16, that is fast upon the outer end of a rod, 25, which is mounted so as to turn in standards 26 27, that rise from the shaft 24. Near its inner end the rod 25 carries a iixed arm, 2S, that projects upwardly within such path of travel of the weighted arms 30 40 ot' the governor, that when said arms drop too low, by reason of the improper action of said governor, they will engage said arm 23, and, moving it laterally, cause the rod 25 to rock and turn the cam 1G, so that itwill vibrate the bell-crank lever 14 13 and disengage its dog 15 from the drum 50, and thus permit the spring 23 to operate to close the stop-valve.

A stiftl Hat spring, 29, secured to the shaft 24 presses its free end against the fiat side of the rod 25, Fig. 3, and thus holds the arm 28 upright and the cam 16 in proper position to allow the dog 15 to engage the tooth 4. This spring is provided with a hole, 3, in which a pin, 2, projecting from the rod 25 may enter to lock the rod and prevent its resuming its normal position whenever the arm 2S is struck by the governor and rocks the rod.

The bell-crank 13 14 may be sustained teniporarily in the dotted position, Fig. 2, by means of a pin that projects from the shaft 24, and which engages the slot in a spring-catch, 17, that is attached to the hub 1S of said lever.

The operation is as follows: In starting the engine the steam is admitted by opening the stop-valve, which is accomplished by turning the screw-rod 21 through the rotation ot' the hand-wheel 22. In this operation the drum 5() is revolved, thereby winding up the spring 23.

The screw 11 is then loosened, and the spring is further wound up until its tension is sutcient to rotate the hand-wheel in the reverse direction to such an extent as to close the stop-valve; but instead ot' being allowed to so operate, the bell-crank lever 14 13 is disengaged from the pin 1, and its dog 15 is en gaged with the tooth 4, so as to prevent the rotation of the drum 50. The spring' 29 is also disengaged from the pin 2, and the rod 25 is rocked so as to bring its arm 2S into the position shown in the drawings. It, now, the belt or other gearing causing the rotation of the governor is disarranged, or the governor otherwise becomes inoperative, its weighted arms will drop so as to strike the arm 28, thereby rocking the rod 25 and causing the cam 16 to forceA the arm 14 of the bell-crank outward, thus raising the arm 13 and disengaging the dog 15 from the tooth 4. The drum 50, thus released, will be immediately rotated by the resilient power of the spring 23, and hence rapidly rotate the hand-wheel 22 and screw-rod 21, and quickly close the stopvalve, thus cutting ofi' the supply of steam and causing the engine to stop instantly. In this action ot' the devices the spring 29 will engage the pin 2 and hold the rod 25 in a position to sustain the swell of the cam 16 against the arm 14 ot' the bell-crank, whereby the arm 13 ot' the latter will be held high enough to prevent its dog 15 from obstructing the free rotation ot' the drum 50.

Although this cut-olf mechanism has been particularly described as applied to a steamengine and in connection with a common form of governor, it is to be understood that it will ett'ectually operate with any other kind of motor and governor by simple mechanical adaptations without departing from the scope of the invention.

It may be further observed that a weight or other suitable power may be used in place of the spring 23.

Having thus described my improvements, what I claim is 1. The combination, with the governor, pipe 20, its stop-valve, rod 21, and wheel 22, ofthe shaft 6, carrying the collar 5, spring 23, and drum 50, the bell-crank lever, rod 24, the rod 25, carrying cam 16, and arm 28, substantially as described,

2. rllhe combination, with the governor, pipe 20, its stop-valve, rod 21, and wheel 22, of the shaft 6, carrying the collar 5, spring 23, and drum 50, the bell-crank lever, rod 24, the pin 1, and spring-plate 17, the rod 25, carrying cam 16, arm 28, and the pin 2, and the spring 29, substantially as described.

In testimony whereof` I have hereunto set my hand in the presence of two subscribing witnesses.

GEORGE H. DOUGHERTY.

Vitnesses:

T. H. PALMER, G. H. GRAHAM. 

